Rocky realized he had no chance of beating the Druid head-on. The forest itself was the Druid's weapon, and Rocky was too weak to face it directly.
His only hope to beat him was to find the Druid's source tree, the heart of its power and then destroy the tree, as according to his knowledge about druids, no matter how much he hurt them, within forests where they could simply replace their damaged parts with more dried twigs and trees, the druids moving body was nearly immortal and fighting it head-on was pointless unless he had a way to incinerate the moving body to ashes, which he did not.
Recalling his lessons back at the university, Rocky knew what to look for when searching for a druid's source tree….. he needed to basically search for old looking trees that were unusually large or those that seemed unnaturally vibrant.